1. Section 4: Naming Molecular Compounds and Acids
Chapter 5: Molecules and Compounds
Section 4: Naming Molecular Compounds and Acids

2. Learning Goals Name molecular compounds. Name binary acids.
Name oxyacids containing an oxyanion ending in -ate.
Name oxyacids containing an oxyanion ending in -ite.

3. Naming Molecular Compounds
Remember, nearly all molecular compounds form from two or more nonmetals.
Binary (two-element) molecular compound names have the following form:
name of 1st element
base name of 2nd element + ide
prefix + + +
prefix

4. Naming Molecular Compounds
When writing the name of a molecular compound the first element is the more metal-like one
The prefixes given to each element indicate the number of specific atoms present
mono- 1   hexa- 6
di- 2   hepta- 7
tri octa- 8
tetra- 4   nona-9
penta deca-10

5. Naming Molecular Compounds
If there is only one atom of the first element, the prefix mono- is normally omitted.
CO2
The full name is carbon dioxide.

6. Naming Molecular Compounds
When the prefix ends with a vowel and the base name starts with a vowel, the first vowel is sometimes dropped.
Vowel is dropped in monoxide but not in dioxide or triiodide.

7. Naming Molecular Compounds
N2O
The entire name is dinitrogen monoxide.

8. Practice
CCl4
BCl3
SF6
N2O4

9. Practice Write the formulas for each compound: disulfur tetrafluoride
phosphorus pentafluoride
xenon hexafluoride

10. Naming Acids
The first step in naming an acid compound is identifying it as an acid.
Acids are molecular compounds that form H+ ions when dissolved in water.
Acids will always be aqueous (aq)

11. Naming Acids
They are composed of hydrogen, usually written first in their formula, and one or more nonmetals, written second.

12. Naming Acids We can categorize acids into two groups:
binary acids: those containing only hydrogen and a nonmetal
oxyacids: those containing hydrogen, a nonmetal, and oxygen

13. Naming Acids
Binary acids are composed of hydrogen and a nonmetal. The names for binary acids have the following form:

14. Naming Acids HCl(aq) HBr(aq) HCl(g) hydrochloric acid hydrobromic acid
refers to hydrogen chloride molecules in the gas phase, and not to the acid.

15. Practice
H2S(aq)
HF(aq)

16. Practice Write the formula of each compound: hydroiodic acid
hydrofluoric acid

17. Naming Acids
Oxyacids are acids that contain oxyanions, which can be found in the table of polyatomic ions.
These acids are a combination of one or more H+ ions with an oxyanion.
The number of H+ ions depends on the charge of the oxyanion, so that the formula is always charge-neutral.

18. Naming Acids
The names of acids containing oxyanions ending with -ite take this form:
H2SO3(aq) contains the sulfite (SO32−) ion

19. Naming Acids
The names of acids containing oxyanions ending with -ate take this form:
HNO3(aq) contains the nitrate (NO3−) ion

20. Practice
HC2H3O2(aq)
HNO2(aq)

21. Practice Write the formula for each compound: Nitric acid Nitrous acid
Hypochlorous acid
Perbromic acid

23. Practice
CO(g)
CaF2(aq)
HF(aq)
Fe(NO3)3(s)
HClO4(aq)
H2SO3(aq)